Geometry - Unit 8 Vocabulary

Arc

A connected part of a circle

Area

On a flat surface (plane), the number of non-overlapping square units needed to cover the region

Central Angle

An angle with its vertex at the center of a circle

Circumference

The perimeter of (distance around) a circle

Convex polygon

A polygon where any pair of points inside the polygon can be connected by a segment without leaving the interior of the polygon

Diameter

A line segment drawn through the center of a circle with both endpoints on the circle

Exterior angle

The angle formed when a side of a polygon is extended to form an angle with an adjacent side outside of the polygon

Interior angle

An angle formed by two consecutive sides of the polygon

Linear scale factor

When a two-dimensional figure is enlarged (or reduced) proportionally, its lengths and area change

Non-convex polygon

A polygon that is not convex

Perimeter

The distance around the exterior of a figure on a flat surface

Pi

The ratio of the circumference (C) of the circle to its diameter (d)

Polygon

A two-dimensional closed figure of three or more line segments (sides) connected end to end

Radius

A line segment drawn from the center of a circle to a point on the circle

Regular Polygon

It is a convex polygon with congruent angles and congruent sides

Remote Interior Angle

The two angles not adjacent to the exterior angle

Sector

A region formed by two radii of a central angle and the arc between their endpoints on the circle

Similar

Two shapes that have exactly the same shape but are not necessarily the same size

Zoom Factor

The amount each side of a figure is multiplied by when the figure is proportionally enlarged or reduced in size